This was one of my collaborative projects in college.
In my movement and motion-based drawing class in college, we tried an exercise where each person in the class started with a drawing and then passed it to the next person every ten minutes until everyone had contributed. The original artist then had the last ten minutes with the piece to finish it. This was the drawing that came from my original sheet of paper, where I drew a very simple, geometric outline of a piano, a hand, and music notes.